Skip to main content

Tubing Leak

In this section, we describe the load case Tubing leak, available in Oliasoft WellDesign.#



Tubing leak is a burst load case, where the unknown is the internal pressure profile of the casing / tubing.

NOTE!
In this documentation we denote any tubular as casing or tubing. All calculations however encompass any tubular, such as tubings, casings, liners, tie-backs etc.


Summary#


This load case is used in connection with production- and injection- operations, and represents a surface pressure on top of a completion fluid due to a tubing leak.


Printable Version#


Oliasoft Technical Documentation - Tubing Leak


Inputs#


The following inputs define the tubing leak load case

  1. The true vertical depth (TVD) along the wellbore as a function of measured depth. Alternatively, the wellbore described by a set of survey stations, with complete information about measured depth and inclination.
  2. The true vertical depth / TVD of
    1. The hanger of the tubing, TVDhanger_{hanger}
    2. The shoe of the tubing, TVDshoe_{shoe}
    3. The packer depth, TVDpacker_{packer}
    4. The perforation depth, TVDperforation_{perforation}
  3. The pore pressure profile from hanger to influx depth.
  4. The packer fluid density, ρpacker\rho_{packer}
  5. The temperature at the perforation depth, TperforationT_{perforation}
  6. The gas gravity, sggassg_{gas}

Scenario Illustration



Calculation#


The internal pressure profile of the casing / tubing is calculated as follows

  1. Calculate the pore pressure at perforation depth, pp,perforationp_{p,perforation}

  2. Calculate the gas density at perforation depth from gas gravity, using Sutton correlations, ρgas,perforation\rho_{gas,perforation}

  3. Calculate the pressure at the hanger

    phanger=pp,Β perforationβˆ’Οgas,Β perforation g (TVDperforationβˆ’TVDhanger)β€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€ŠΒ (1)p_\text{hanger} = p_\text{p, perforation} - \rho_\text{gas, perforation}\, g\, (\text{TVD}_{\text{perforation}} - \text{TVD}_{\text{hanger}}) \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (1)

    where gg is the gravitational constant.

  4. The internal pressure of the tubing depends on where the packer- and perforation- depth are related to each other and the shoe of the tubing. Explicitly, parametrize the tubing by TVD

    1. If TVDshoe≀TVDpacker≀TVDperforation\text{TVD}_\text{shoe} \leq \text{TVD}_\text{packer} \leq \text{TVD}_\text{perforation}, or if TVDshoe≀TVDperforation≀TVDpacker\text{TVD}_\text{shoe} \leq \text{TVD}_\text{perforation} \leq \text{TVD}_\text{packer}, then

      pi=phanger+ρpacker g (TVDβˆ’TVDhanger)β€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€ŠΒ (2)p_i = p_\text{hanger} + \rho_\text{packer}\, g\, (\text{TVD} - \text{TVD}_{\text{hanger}}) \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (2)

    2. If TVDpacker≀TVDshoe≀TVDperforation\text{TVD}_\text{packer} \leq \text{TVD}_\text{shoe} \leq \text{TVD}_\text{perforation}, then from hanger to packer

      pi=phanger+ρpacker g (TVDβˆ’TVDhanger),β€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€ŠΒ (3)p_i = p_\text{hanger} + \rho_\text{packer}\, g\, (\text{TVD} - \text{TVD}_{\text{hanger}}), \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (3)

      and from packer to shoe

      pi=pperforationβˆ’Οgas,Β perforation g (TVDperforationβˆ’TVD).β€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€ŠΒ (4)p_i = p_\text{perforation} - \rho_\text{gas, perforation}\, g\, (\text{TVD}_\text{perforation} - \text{TVD}). \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (4)

    3. If TVDpacker≀TVDperforation≀TVDshoe\text{TVD}_\text{packer} \leq \text{TVD}_\text{perforation} \leq \text{TVD}_\text{shoe}, then from hanger to packer

      pi=phanger+ρpacker g (TVDβˆ’TVDhanger)β€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€ŠΒ (5)p_i = p_\text{hanger} + \rho_\text{packer}\, g\, (\text{TVD} - \text{TVD}_{\text{hanger}}) \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (5)

      from packer to perforation

      pi=pperforationβˆ’Οgas,Β perforation g (TVDperforationβˆ’TVD)β€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€ŠΒ (6)p_i = p_\text{perforation} - \rho_\text{gas, perforation}\, g\, (\text{TVD}_\text{perforation} - \text{TVD}) \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (6)

      and finally from perforation to shoe

      pi=pperforation+ρpacker g (TVDβˆ’TVDperforation)β€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€ŠΒ (7)p_i = p_\text{perforation} + \rho_\text{packer}\, g\, (\text{TVD} - \text{TVD}_\text{perforation}) \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (7)

    4. If 4.1 = 4.2, then from hanger to perforation

      pi=phanger+ρpacker g (TVDβˆ’TVDhanger)β€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Š(8)p_i = p_\text{hanger} + \rho_\text{packer}\, g\, (\text{TVD} - \text{TVD}_{\text{hanger}}) \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;(8)

      and from perforation to shoe

      pi=pperforation+ρpacker g (TVDβˆ’TVDperforation).β€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€Šβ€…β€ŠΒ (9)p_i = p_\text{perforation} + \rho_\text{packer}\, g\, (\text{TVD} - \text{TVD}_\text{perforation}). \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (9)

    5. The last scenario, TVDperforation≀TVDpacker≀TVDshoe\text{TVD}_\text{perforation} \leq \text{TVD}_\text{packer} \leq \text{TVD}_\text{shoe}, is physically impossible


References#


[1] Curtis H. Whitson and Michael R. Brule ́. Phase behavior, volume 20 of Henry L. Doherty series. SPE Monograph series, 2000.

[2] Sutton, R.P.: β€œCompressibility Factors for High-Molecular Weight Reservoir Gases,” paper SPE 14265 presented at the 1985 SPE Annual, Technical Conference and Exhibition, Las Vegas, Nevada, 22–25 September.